The current UK standard for the determination of loading on temporary road
signs is generally perceived by the industry to be unrealistic, in that no
account is taken of vehicle induced forces. To enable a rational revision o
f the standard to take place full scale data have been collected on the veh
icle induced force acting on a representative range of 750 mm. road signs,
1500 mm road signs and a pedestrian barrier. Preliminary measurements showe
d that wind and vehicle effects could be treated separately (to first order
) because vehicle induced forces are related to the instantaneous pressure
field generated by the vehicle motion rather than due to air movement. The
results have been expressed as non-dimensional coefficients of force based
on sign area and nominal vehicle speed. Sign shape appears to have no signi
ficant effect on the magnitude of the vehicle induced force coefficient. No
minal sign size (750 or 1500 mm) appears to have some effect on the overall
force coefficient, with larger signs experiencing a longer period of expos
ure, at a slightly lower magnitude, to vehicle induced forces. In all cases
where signs are positioned perpendicular to the vehicle motion the peak fo
rce is identified as being in the opposite direction to the vehicle motion
as the front of the vehicle passes the sign. The results presented form par
t of a wider study, which included the wind and vehicle induced effects on
flat plates in the atmospheric boundary layer. (C) 2001 Elsevier Science Lt
d. All rights reserved.